1. Field of the Invention
The present invention relates to electronic devices worn on the wrist, and more particularly, to such devices having separate electronic components.
2. Description of the Prior Art
Electronic devices such as clocks and even calculators have become sufficiently compact and light-weight to be worn on the wrist. These devices typically have a control circuit which performs the time-keeping (or calculating) functions. A second major component of the device is the display circuit which provides the output (e.g., the time-of-day) of the control circuitry in a form readable by the human user. These display circuits typically utilize LCD's (liquid crystal displays) or LED's (light emitting diodes) to form the alpha-numeric characters. A third major component is the power source, usually a battery, which provides the electrical energy to power the control circuitry and display.
The display circuit, control circuit and battery have usually been housed into a single module since these components must be electrically coupled together. As a result, the watch or calculator module which is attached to a wrist band, tends to be rather bulky and top heavy, particularly where the housing is made of metal.
In order to reduce the size of the module, an alternative approach has been taken in which the control circuitry (and/or battery) have been housed in a separate module typically worn on the other side of the wrist. Consequently, this has necessitated an electrical connection through the wrist band between the various modules attached to the wrist band.
One approach for accomplishing such an electrical connection between modules is suggested in U.S. Pat. No. 4,194,355 to Nishida. There, electrical connector wires embedded in the wrist band each have an individual terminal at the end of the wrist band. These wrist band terminals form a plug which mates with electrical connectors of a display module. Although the connector scheme suggested in this reference allows the electronic components of the device to be distributed into two modules, the interconnection between the wrist band and the display module is somewhat complicated and therefore relatively expensive to manufacture.
Furthermore, the length of the wrist band between the display module and the other module is fixed once the terminal plug is attached to the end of the wrist band at the factory. As a result, the length of the wrist band between the display module and the separate electronics module cannot be easily adjusted to accommodate various wrist sizes.